It is widely accepted that infrared energy is superior to other forms of heat energy for certain industrial curing and drying processes. In the past 10-15 years, infrared energy generated from fuels such as butane, propane and natural gas has also become popular for use in outdoor grills and for indoor grills used in restaurants. All of these gas fired grills depend upon the combustion of a gaseous fuel for the generations of infrared energy. It is quite simple to achieve radiative heat flux levels high enough to sear meat and to cook it quickly. Such meats include steaks, chops, hamburgers, ribs and small roasts. A hamburger with a diameter of about 5 inches (12.7 cm) and % inch (1.3 cm) thickness weighing about 0.40 pounds (0.18 kg) can be broiled to an internal temperature of 160° F. (71° C.) in less than 10 minutes.
All gas burners that depend on a venturi or an air injector tube to introduce primary air for combustion have a minimum fuel input for low fire. This restriction limits most infrared energy types of grills for use in slow cooking over an extended period of time because the limitation of the turn down ratio does not allow the infrared energy to be reduced to a level required—less than a total emissive power of about 1000 BTU/HR FT2—for traditional slow cooking, barbecuing, and smoking that can take up to 12-14 hours or more.
A growing interest in slow cooking and smoking in recent years has spawned a rapidly growing sector of the outdoor cooking equipment industry, a sector which includes traditional smokers as well as kamado-style ceramic cookers and pellet grills. However, these types of cookers are not capable of reaching the high searing temperatures of infrared grills. An apparatus that can reduce the total emissive power of infrared grills and can be installed on and removed from a grill easily would make infrared grills far more versatile by enabling consumers to slow cook and smoke as well as sear on the same piece of cooking equipment.